Rope pay-out apparatus



p 1968 K- E. REISCHL 3,399,868

ROPE PAY-OUT APPARATUS Filed March 51, 1967 INVENTOR KARL E. REISCHLATTORNEY United States Patent 3,399,868 ROPE PAY-OUT APPARATUS Karl E.Reischl, South Milwaukee, Wis, assignor to Bucyrus-Erie Company, SouthMilwaukee, Wis., a corporation of Delaware Filed Mar. 31, 1967, Ser. No.627,552 8 Claims. (Cl. 254-1753) ABSTRACT OF THE DISCLOSURE A cable drumis connected through a gear train containing a sprag clutch to drive anhydraulic pump when it pays out cable. The cable passes over a sheaveand is held against the sheave by a roller under pressure from anhy'draulic cylinder. A gear with sloping friction surfaces is geardriven from an hydraulic motor and the friction surfaces are held indriving engagement with the groove of the sheave by another hydrauliccylinder. The hydraulic pump energizes both hydraulic cylinders and therotary hydraulic motor to pull the cable from the drum during pay out.

Background of the invention An hydraulic crane for oceanographic uses,such as retrieving research submarines, must have a cable sufficientlyheavy to sustain heavy loads; but the hook at the end of the cable mustbe as light as possible to minimize the danger of injury to divers ordamage to water craft. When the power winch for the cable is mounted ator near the foot of the boom of the crane, the weight of the hook andlength of cable hanging from the boom is insufficient to pull the cableaway from the Winch when it pays out the cable. Hence, a positive payout for the cable is needed; and since the speed of pay out may have torespond accurately from speeds of zero feet per minute to three hundredfeet per minute, the response of the rope pay out must be precise.Finally, the positive pay-out apparatus must not impose a load on thecable or winch when the winch is winding in cable, and its weight, costand complexity must be minimized.

The present invention solves those problems effectively and efficiently.Since such a rope pay out will have utility in many other devices inaddition to oceanographic cranes, the invention is not to be consideredas limited to oceanographic cranes. For example, in the prior art,positive rope pay-out devices have been used with log skidders, US.Patent No. 2,141,469, and with traveling cranes, US. Patent No.2,359,073, where the cable winch has a stationary mounting and the cableis carried horizontally by a. carriage supported on cables or beams.However, those devices cannot achieve the precision operation of thepresent invention, nor do they provide for release of the cable when payout ceases; but to the extent that the prior art approached suchresults, the weight, cost and complexity of the gear required wasprohibitive.

Summary of the invention The present invention resides in thecombination of a power-driven cable drum and a cable sheave remote fromthe drum, along with a fluid pump which is driven by said drum when saiddrum pays out cable, a rotary fluid motor which is driven by fluid fromsaid pump, and a linear fluid actuator which is also driven by fluidfrom said pump and which acts to move said rotary fluid motor intodriving relationship with said sheave.

Brief description of the drawings FIG. 1 is a side elevation of anembodiment of the present invention in a crane having a jib pivotallymounted on it.

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FIG. 2 is a top view partially in section of the sheave and sheave drivemechanism taken along the line 22 in FIG. 1.

FIG. 3 is a schematic representation of the hydraulic circuitry of theembodiment of the invention shown in FIG. 1.

FIG. 4 is a rear elevation of a portion of the apparatus shown in FIG. 1illustrating the drive for the hydraulic pump.

Description of the preferred embodiment FIG. 1 illustrates an embodimentof the present invention on a crane similar to the oceanographic cranedisclosed in my co-pending application entitled Crane Jib, Ser. No.628,934 filed on Apr. 6, 1967. The only parts of the crane structureshown in FIG. 1 are those that relate directly to the present invention,and they include aboom 1 and a main jib 2, which is suspended from apivotal mounting 3 on the underside of the boom 1. Further detail of thestructure of this crane can be obtained by reference to theabove-mentioned co-pending application. Suffice it for the purposes ofthis application to show a foot end 4 of the boom 1 with a main cabledrum 5 mounted on top of the foot end 4 of the boom 1. The main cabledrum is 5 power driven by hydraulic motors (not shown), it has a mainWorking cable 6 Wound upon it. The cable 6 extends from the cable drumto a sheave 7 which is pivotally mounted coaxial with the pivotalmounting 3 of the main jib 2. After passing over the sheave 7, the mainworking cable 6 passes down between a pair of pulleys (not shown) at theopposite end of the main jib 2 (not shown), and it has a light Weighthook (not shown) on its opposite end for lifting objects such as smallvessels, or submarines used in oceanographic exploration.

The sheave 7 is shown (in section in FIG. 2) pivotally mounted about ashaft 8, which is concentric with the pivotal mounting 3 of the main jib2. On one side of the sheave 7 there is a friction drive and gear wheel9 that has row of teeth 10 about the center of its circumference andtapered frictional drive surfaces 11 and 12 on each side of the teeth10. The tapered friction drive surfaces 11 and 12 engage opposite walls13 and 14 of a cable groove 15 formed in the center of the circumferenceof the sheave 7. On the other side of the sheave 7, a freely rotatablegrooved roller 16 bears against the cable 6 in the bottom of the cablegroove 15 of the sheave 7 to hold the cable 6 in frictional drivingengagement with the sheave 7. The teeth 10 of the gear wheel 9 aredrivingly engaged by a pinion 17; and when the pinion 17 drives the gearwheel 9, the frictional drive surfaces 11 and 12 on the gear wheel 9engaging the walls 13 and 14 of the cable groove 15 of the sheave 7rotate the sheave 7. The grooved roller 16 holds the cable 6 against thecable groove 15 of the rotating sheave 7, and thus the cable 6 isdriven, or positively paid out, by the sheave 7.

The main cable drum 5 on the foot end 4 of the boom 1 is coupled througha gear train 18 to drive a fluid pump 19, which in this embodiment ispreferably a vane-type hydraulic pump, or an axial piston hydraulicpump. The gear train 18, which couples the cable drum 5 to the fluidpump, 19, is made up of a gear wheel 20 that is mounted to rotate withthe cable drum 5, and a pinion 21 that is drivingly engaged by the gearwheel 20 and mounted on a common shaft 22 with the second gear wheel 23.To complete the gear train 18, the gear wheel 23 engages a gear wheel 24that drives the drive shaft 25 of the fluid pump 19. FIG. 4 illustratesa portion of the pinion 21, common shaft 22, and gear wheel 23 on thecommon shaft 22, and the gear wheel 24 on the drive shaft 25, and itshows the gear wheel 24 fastened to the driving element 26 of a spragclutch 27, so that a driven element 28 of the sprag clutch 27 can bemounted on the drive shaft of the fluid pump 19. Thus, the gear train 18serves two functions: first, the one-way clutch 27 allows the cable drum5 to drive the pump 19 only when the cable drum 5 is paying out cable 6;and secondly, it gears up the rotational drive speed from the main cabledrum 5 to ensure that the fluid pump 19 will be driven at an efficientspeed even when the cable drum 5 is paying out cable 6 at the slowestpossible rate.

The fluid pump 19 is connected through fluid circuitry 29 to a rotaryfluid motor 30 and two linear fluid motors 31 and 32, which are mountedon the end of the main jib 2. The linear fluid motors 31 and 32, whichare single action hydraulic cylinders, are end mounted on brackets 33and 34 on opposite sides of the main jib 2. A pair of arms 35 and 36 arepivotally mounted at one end about a pin 37 on the main jib 2 justbeneath the sheave 7. The arm 35 on the left of the drawing, oppositeits pivotally mounted end, has a free, forked end 38, in which thegroove roller 16 is rotatably mounted, and the linear motor 31 has itspiston rod 39 fastened to act upon the forked end 38 of the arm 35. Theother linear motor 32 on the opposite side of the main jib 2 has itspiston rod 40 fastened to a forked end 41 opposite from the pivotallymounted end of the arm 36, and the friction drive and gear wheel 9 ismounted in forked end 41 of the arm 36. The forked end 41 of the arm 36also has projections 42 extending from it, which support the rotaryhydraulic motor 30 and a gear train 43 for coupling the pinion 17, andthus the gear wheel 9, to be driven by the rotary motor 30. The geartrain 43 includes a gear 44 on the shaft 45 of the rotary motor 30, anda gear 46 with the pinion 17 on a shaft 47 mounted on the projections 42of the forked end 41 of the arm 36, and the gear 46 is engaged by thedrive gear 44 on the motor shaft 45. Each of the arms 35 and 36 isbiased away from the sheave 7 by extension springs 48 and 49,respectively, to hold the drive gear wheel 9 normally out of engagementwith the sheave 7 and the grooved roller 16 normally out of engagementwith the cable 6 on the sheave 7.

When the cable drum 5 is driven by its drive source to wind in on thecable 6, the sprag clutch 27 prevents rotation of the drum 5 from actingon the fluid pump 19, and therefore the drive gear wheel 9 and thegrooved roller 16 are held out of engagement with the sheave 7 and thecable 6, respectively, so that the wind in of the cable 6 is free fromany additional drag occasioned by the positive pay-out mechanism.However, when the cable drum 5 is driven to pay out on cable 6, therotation of the cable drum drives the fluid pump 19 at a speedproportional to the rate of pay out. When the fluid pump 19 is driven,it actuates the rotary hydraulic motor 30 and the linear hydraulicmotors 31 and 32. The linear motors 31 and 32, respectively, drive thegrooved roller 16 into engagement with the cable 6 on the sheave 7 andthe drive gear wheel 9 into a frictional driving engagement with thewalls 13 and 14 of the cable groove 15 of the sheave 7, and the rotarymotor 30 driving the friction drive gear wheel 9 through the gear train43 causes the sheave 7 to rotate at a speed proportional to the speed ofthe main cable drum. The ratios of the gear train 18 driving the fluidpump 19 and the gear train 43 driving the friction drive gear wheel 9are such that the sheave 7 is always driven approximately 5% faster thanthe main cable drum 5. This feature provides a constant tension in themain cable 6, regardless of the speed of pay out, which is the same asthe cable 6 and cable drum 5 would experience if there were a heavyweight on the end of the cable 6.

FIG. 3 illustrates in schematic arrangement the apparatus discussedabove in conjunction with the fluid circuitry 29 by which it operates. Asuction line 51 connects the suction side of the hydraulic pump 19 witha reservoir 52, and a working line 53 connects the discharge side of thehydraulic pump 19 with the linear motors 31 and 32 and the pressure sideof the rotary motor 30. A return line 54 connects the other side of therotary motor 30 to the reservoir 52. Hence, the linear motors 31 and 32and the rotary motor 30 are connected in parallel to the working line53. In parallel with the rotary motor 30 joining the working line 53 andthe return line 54 is a bleed line 55, which contains, in series, arestricted orifice 56, which in this embodiment is variable and would bea needle valve, and a spring loaded check valve 57, which allows fluidunder pressure to flow in one direction only, viz, from the workingconduit 53 to the return conduit 54. A check valve 58 is inserted in thesuction line 51 inside the reservoir 52 to hold fluid in the suctionline 51 when the pump 19 is not operating. A relief line 59 containing apressure relief valve 60 connects the working line 53, adjacent the pump19 to the reservoir 52. Finally, a drain line 61 from the rotary motor30 empties into the reservoir 52.

When the hydraulic pump 19 is driven by the cable drum 5 as it pays outcable 6, hydraulic fluid is pumped from the reservoir 52 through thesuction line 51 and the hydraulic pump 19 to the main working line 53.This hydraulic fluid under pressure simultaneously actuates the twolinear motors 31 and 32 and the rotary motor 30, with the portion of thefluid that actuates the rotary motor 30 returning to the reservoir 52through the return line 54. When the rope pay out is stopped and thepump 19 ceases to pump fluid, a slight relaxation in fluid pressure isachieved through the spring loaded check valve 57 and the restrictedorifice 56 in the bleed line as the return springs 48 and 49 draw thegrooved roller 16 and the friction drive gear wheel 9, respectively,away from the sheave 7, forcing the piston rods 39 and 40 into theirhydraulic motors 31 and 32, respectively. However, the springloadedcheck valve 57 closes as soon as the fluid pressure drops below thespring loading to maintain the fluid in the main working line 53 so thatthe next time the main cable drum 5 begins to pay out cable 6, the ropepay out apparatus will respond instantly with the first energization ofthe pump 19. Also the check valve 58 in the reservoir maintains fluid inthe suction line 51 to provide immediate supply to the pump 19. Bycontrast, if the fluid were allowed to drain out of the main workingline 53 or the suction line 51 when the pump 19 is not operating, asubstantial delay could result when rope pay out is again started whilethe pump 19 would refill the working conduit 53 and build up suflicientpressure to drive the motors 30, 31 and 32. During that delay, the cable5 could become fouled.

The restricted orifice 56 in the bleed line 55 will allow a continuousdischarge of hydraulic fluid from the working conduit 53 to the returnconduit 54, but the volume of fluid flow through that restricted orifice56 is so minuscule as to have no adverse effect on the operation of thesystem. However, the bleed through the restricted orifice 56 issufiicient to permit the piston rods 39 and 40 of the linear motors 31and 32 to be retracted to /2 inch in order to provide the necessary f or5 inch clearance between the sheave 7 and the friction drive gear wheel9 and between the cable 6 on the sheave 7 and the grooved roller 16,when the pressure of the fluid is relaxed. The relief valve in therelief line 59 is set to maintain the desired pressure in the workingline 53, but to spill over in the event an overload does develop.

Of course, it will be apparent that common substitutions may be made inthis embodiment of the invention without departing from the scope of theinvention. For example, the linear motors 31 and 32 in this embodimentare singleacting hydraulic cylinders or rams; but for the short distanceof operation employed here, a diaphragm or other type of linear actuatormight also be used. The spring return effected by the external biasingsprings 48 and 49 might also be achieved with an internal spring insideof the linear motors 31 and 32, or some other such variation. There aremany different types of rotary motors 30,

any one of which could be used if desired. The same is true of therotary vane pump 19.

In some applications it may also be possible to eliminate the bleed line55, and allow the fluid from the release of the linear motors 31 and 32to bleed through a fractional rotation of the rotary motor 30'. In suchan embodiment it may be desirable to insert a light back pressured motordischarge check valve (not shown) in the drain line 54 to prevent adraining developing in the drain line 54 due to oil gravity when thesystem is deenergized to cause a syphoning of fluid through the motor 30back to the tank 52. There are, of course, any number of still furthersubstitutions and modifications that could be made to arrive atadditional embodiments of this invention, but these need not becatalogued here. The invention, in its full scope, is set forth in theclaims that follow.

I claim:

1. A positive cable pay-out apparatus comprising the combination of adrum power driven to wind in and pay out cable;

a sheave rotatably mounted remote from said drum to receive said cableon it;

a coupling means connecting said power-driven drum to said fluid pump todrive said fluid pump when said drum pays out said cable;

a rotary motor driven by fluid from said fluid pump;

a sheave drive means connected to be driven by said rotary motor torotate said sheave and adapted to be placed in and out of drivingengagement with said sheave;

a linear motor means driven by fluid from said fluid pump, and mountedto automatically place said sheave drive means into driving engagementwith said sheave;

and fluid circuitry including a reservoir and interconnecting saidreservoir, said pump, said rotary motor and said linear motor.

2. A positive cable pay-out apparatus as set forth in claim 1 includingmeans for holding said cable in frictional driving engagement with saidsheave only when said rotary motor is driven by fluid from said pump.

3'. A positive cable pay-out apparatus as set forth in claim 2 whereinsaid means for holding said cable in frictional driving engagement withsaid sheave includes a grooved roller movably mounted to engage saidcable on said sheave and connected to said linear motor means to bemoved thereby into engagement with said cable on said sheave only whensaid rotary motor is driven by fluid from said pump.

4. A positive cable pay-out apparatus as set forth in claim 1 whereinsaid fluid circuitry includes a conduit connecting said reservoir tosaid fluid pump, a second conduit connecting said pump to said rotarymotor and said linear motor means and a third conduit connecting saidrotary motor and said linear motor means to said reservoir;

said linear motor means and said rotary motor are connected in parallelacross said second and said third conduits;

and a bleed line having a restricted orifice and spring loaded checkvalve permitting flow of an amount of fluid only sufficient to relaxfluid pressure when rope pay out ceases is connected across said secondand third conduits.

5. A positive cable pay-out apparatus as set forth in claim 4 wherein acheck valve is mounted in said second conduit between said fluid pumpand both said pilot line and said linear and rotary motors permittingfluid flow from said pump to said linear and rotary motors;

a check valve is mounted in said pilot line permitting fluid flow fromsaid second conduit to said third conduit;

said second conduit is connected to said reservoir through a pressurerelief valve;

and a drain line is connected from said rotary motor to said reservoir.

6. A positive cable pay-out apparatus as set forth in claim 1 whereinsaid coupling connecting said power-driven drum to said fluid pump is agear train including a one-way clutch to transmit force only when saidpower-driven drum pays out said cable. 7, A positive cable pay-outapparatus as set forth in claim 1 wherein said sheave drive meansincludes a movably mounted gear wheel connected by a gear train to bedriven by said rotary motor, and said gear wheel has friction surfacesengageable with the groove of said sheave to drive said sheave and isnormally spring biased out of engagement with said sheave groove; andsaid linear motor means includes a single action hydraulic cylinderconnected to said movably mounted gear wheel to force said gear wheelinto friction driving engagement with said sheave groove when said fluidpump is driven. 8. A positive cable pay-out apparatus as set forth inclaim 1 wherein said apparatus is mounted on a crane having a boom, ajib pivotally suspended from said boom, and a cable for lifting loads onsaid jib and extending from a free end of said jib to a foot of saidboom;

r said power-driven drum is mounted on said foot of said 4 boom;

and said sheave is mounted coaxial with the pivotal suspension of saidjib from said boom.

References Cited UNITED STATES PATENTS 2,279,853 4/1942 White 254175.72,283,321 5/1942 Doe 53 2,436,510 2/1948 Ferguson 254-1391 3,005,62210/1961 Garnier 254 17s.7

FOREIGN PATENTS 1,203,759 1/1960 France.

60 RICHARD E. AEGERTER, Primary Examiner.

H. C. HORNSBY, Assistant Examiner.

